> Unless your Subversion server will be *extremely* busy or the data
> safey is extremely critical you shouldn't need anything other than
> RAID 1. The probability of two disks crashing at the same time is
> very low and in that case you would still have your nightly backups.
>
> Hope this helps.
>
> Best Regards,
> Michael Goettsche
> svn-hosting.com - Professional Subversion and Trac Hosting

I tend to throw out the RAID, and use a nightly disk mirror on the second
disk. The far likelier cause of file loss is operator error, not disk
failure in my experience, and it's a lot easier to recover the files from a
read-only repository.